diff options
Diffstat (limited to 'src/libvorbis-1.3.4/lib/sharedbook.c')
| -rw-r--r-- | src/libvorbis-1.3.4/lib/sharedbook.c | 579 |
1 files changed, 579 insertions, 0 deletions
diff --git a/src/libvorbis-1.3.4/lib/sharedbook.c b/src/libvorbis-1.3.4/lib/sharedbook.c new file mode 100644 index 00000000..250717da --- /dev/null +++ b/src/libvorbis-1.3.4/lib/sharedbook.c @@ -0,0 +1,579 @@ +/******************************************************************** + * * + * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. * + * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS * + * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE * + * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. * + * * + * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 * + * by the Xiph.Org Foundation http://www.xiph.org/ * + * * + ******************************************************************** + + function: basic shared codebook operations + last mod: $Id: sharedbook.c 19057 2014-01-22 12:32:31Z xiphmont $ + + ********************************************************************/ + +#include <stdlib.h> +#include <math.h> +#include <string.h> +#include <ogg/ogg.h> +#include "os.h" +#include "misc.h" +#include "vorbis/codec.h" +#include "codebook.h" +#include "scales.h" + +/**** pack/unpack helpers ******************************************/ +int _ilog(unsigned int v){ + int ret=0; + while(v){ + ret++; + v>>=1; + } + return(ret); +} + +/* 32 bit float (not IEEE; nonnormalized mantissa + + biased exponent) : neeeeeee eeemmmmm mmmmmmmm mmmmmmmm + Why not IEEE? It's just not that important here. */ + +#define VQ_FEXP 10 +#define VQ_FMAN 21 +#define VQ_FEXP_BIAS 768 /* bias toward values smaller than 1. */ + +/* doesn't currently guard under/overflow */ +long _float32_pack(float val){ + int sign=0; + long exp; + long mant; + if(val<0){ + sign=0x80000000; + val= -val; + } + exp= floor(log(val)/log(2.f)+.001); //+epsilon + mant=rint(ldexp(val,(VQ_FMAN-1)-exp)); + exp=(exp+VQ_FEXP_BIAS)<<VQ_FMAN; + + return(sign|exp|mant); +} + +float _float32_unpack(long val){ + double mant=val&0x1fffff; + int sign=val&0x80000000; + long exp =(val&0x7fe00000L)>>VQ_FMAN; + if(sign)mant= -mant; + return(ldexp(mant,exp-(VQ_FMAN-1)-VQ_FEXP_BIAS)); +} + +/* given a list of word lengths, generate a list of codewords. Works + for length ordered or unordered, always assigns the lowest valued + codewords first. Extended to handle unused entries (length 0) */ +ogg_uint32_t *_make_words(char *l,long n,long sparsecount){ + long i,j,count=0; + ogg_uint32_t marker[33]; + ogg_uint32_t *r=_ogg_malloc((sparsecount?sparsecount:n)*sizeof(*r)); + memset(marker,0,sizeof(marker)); + + for(i=0;i<n;i++){ + long length=l[i]; + if(length>0){ + ogg_uint32_t entry=marker[length]; + + /* when we claim a node for an entry, we also claim the nodes + below it (pruning off the imagined tree that may have dangled + from it) as well as blocking the use of any nodes directly + above for leaves */ + + /* update ourself */ + if(length<32 && (entry>>length)){ + /* error condition; the lengths must specify an overpopulated tree */ + _ogg_free(r); + return(NULL); + } + r[count++]=entry; + + /* Look to see if the next shorter marker points to the node + above. if so, update it and repeat. */ + { + for(j=length;j>0;j--){ + + if(marker[j]&1){ + /* have to jump branches */ + if(j==1) + marker[1]++; + else + marker[j]=marker[j-1]<<1; + break; /* invariant says next upper marker would already + have been moved if it was on the same path */ + } + marker[j]++; + } + } + + /* prune the tree; the implicit invariant says all the longer + markers were dangling from our just-taken node. Dangle them + from our *new* node. */ + for(j=length+1;j<33;j++) + if((marker[j]>>1) == entry){ + entry=marker[j]; + marker[j]=marker[j-1]<<1; + }else + break; + }else + if(sparsecount==0)count++; + } + + /* sanity check the huffman tree; an underpopulated tree must be + rejected. The only exception is the one-node pseudo-nil tree, + which appears to be underpopulated because the tree doesn't + really exist; there's only one possible 'codeword' or zero bits, + but the above tree-gen code doesn't mark that. */ + if(sparsecount != 1){ + for(i=1;i<33;i++) + if(marker[i] & (0xffffffffUL>>(32-i))){ + _ogg_free(r); + return(NULL); + } + } + + /* bitreverse the words because our bitwise packer/unpacker is LSb + endian */ + for(i=0,count=0;i<n;i++){ + ogg_uint32_t temp=0; + for(j=0;j<l[i];j++){ + temp<<=1; + temp|=(r[count]>>j)&1; + } + + if(sparsecount){ + if(l[i]) + r[count++]=temp; + }else + r[count++]=temp; + } + + return(r); +} + +/* there might be a straightforward one-line way to do the below + that's portable and totally safe against roundoff, but I haven't + thought of it. Therefore, we opt on the side of caution */ +long _book_maptype1_quantvals(const static_codebook *b){ + long vals=floor(pow((float)b->entries,1.f/b->dim)); + + /* the above *should* be reliable, but we'll not assume that FP is + ever reliable when bitstream sync is at stake; verify via integer + means that vals really is the greatest value of dim for which + vals^b->bim <= b->entries */ + /* treat the above as an initial guess */ + while(1){ + long acc=1; + long acc1=1; + int i; + for(i=0;i<b->dim;i++){ + acc*=vals; + acc1*=vals+1; + } + if(acc<=b->entries && acc1>b->entries){ + return(vals); + }else{ + if(acc>b->entries){ + vals--; + }else{ + vals++; + } + } + } +} + +/* unpack the quantized list of values for encode/decode ***********/ +/* we need to deal with two map types: in map type 1, the values are + generated algorithmically (each column of the vector counts through + the values in the quant vector). in map type 2, all the values came + in in an explicit list. Both value lists must be unpacked */ +float *_book_unquantize(const static_codebook *b,int n,int *sparsemap){ + long j,k,count=0; + if(b->maptype==1 || b->maptype==2){ + int quantvals; + float mindel=_float32_unpack(b->q_min); + float delta=_float32_unpack(b->q_delta); + float *r=_ogg_calloc(n*b->dim,sizeof(*r)); + + /* maptype 1 and 2 both use a quantized value vector, but + different sizes */ + switch(b->maptype){ + case 1: + /* most of the time, entries%dimensions == 0, but we need to be + well defined. We define that the possible vales at each + scalar is values == entries/dim. If entries%dim != 0, we'll + have 'too few' values (values*dim<entries), which means that + we'll have 'left over' entries; left over entries use zeroed + values (and are wasted). So don't generate codebooks like + that */ + quantvals=_book_maptype1_quantvals(b); + for(j=0;j<b->entries;j++){ + if((sparsemap && b->lengthlist[j]) || !sparsemap){ + float last=0.f; + int indexdiv=1; + for(k=0;k<b->dim;k++){ + int index= (j/indexdiv)%quantvals; + float val=b->quantlist[index]; + val=fabs(val)*delta+mindel+last; + if(b->q_sequencep)last=val; + if(sparsemap) + r[sparsemap[count]*b->dim+k]=val; + else + r[count*b->dim+k]=val; + indexdiv*=quantvals; + } + count++; + } + + } + break; + case 2: + for(j=0;j<b->entries;j++){ + if((sparsemap && b->lengthlist[j]) || !sparsemap){ + float last=0.f; + + for(k=0;k<b->dim;k++){ + float val=b->quantlist[j*b->dim+k]; + val=fabs(val)*delta+mindel+last; + if(b->q_sequencep)last=val; + if(sparsemap) + r[sparsemap[count]*b->dim+k]=val; + else + r[count*b->dim+k]=val; + } + count++; + } + } + break; + } + + return(r); + } + return(NULL); +} + +void vorbis_staticbook_destroy(static_codebook *b){ + if(b->allocedp){ + if(b->quantlist)_ogg_free(b->quantlist); + if(b->lengthlist)_ogg_free(b->lengthlist); + memset(b,0,sizeof(*b)); + _ogg_free(b); + } /* otherwise, it is in static memory */ +} + +void vorbis_book_clear(codebook *b){ + /* static book is not cleared; we're likely called on the lookup and + the static codebook belongs to the info struct */ + if(b->valuelist)_ogg_free(b->valuelist); + if(b->codelist)_ogg_free(b->codelist); + + if(b->dec_index)_ogg_free(b->dec_index); + if(b->dec_codelengths)_ogg_free(b->dec_codelengths); + if(b->dec_firsttable)_ogg_free(b->dec_firsttable); + + memset(b,0,sizeof(*b)); +} + +int vorbis_book_init_encode(codebook *c,const static_codebook *s){ + + memset(c,0,sizeof(*c)); + c->c=s; + c->entries=s->entries; + c->used_entries=s->entries; + c->dim=s->dim; + c->codelist=_make_words(s->lengthlist,s->entries,0); + //c->valuelist=_book_unquantize(s,s->entries,NULL); + c->quantvals=_book_maptype1_quantvals(s); + c->minval=(int)rint(_float32_unpack(s->q_min)); + c->delta=(int)rint(_float32_unpack(s->q_delta)); + + return(0); +} + +static ogg_uint32_t bitreverse(ogg_uint32_t x){ + x= ((x>>16)&0x0000ffffUL) | ((x<<16)&0xffff0000UL); + x= ((x>> 8)&0x00ff00ffUL) | ((x<< 8)&0xff00ff00UL); + x= ((x>> 4)&0x0f0f0f0fUL) | ((x<< 4)&0xf0f0f0f0UL); + x= ((x>> 2)&0x33333333UL) | ((x<< 2)&0xccccccccUL); + return((x>> 1)&0x55555555UL) | ((x<< 1)&0xaaaaaaaaUL); +} + +static int sort32a(const void *a,const void *b){ + return ( **(ogg_uint32_t **)a>**(ogg_uint32_t **)b)- + ( **(ogg_uint32_t **)a<**(ogg_uint32_t **)b); +} + +/* decode codebook arrangement is more heavily optimized than encode */ +int vorbis_book_init_decode(codebook *c,const static_codebook *s){ + int i,j,n=0,tabn; + int *sortindex; + memset(c,0,sizeof(*c)); + + /* count actually used entries */ + for(i=0;i<s->entries;i++) + if(s->lengthlist[i]>0) + n++; + + c->entries=s->entries; + c->used_entries=n; + c->dim=s->dim; + + if(n>0){ + + /* two different remappings go on here. + + First, we collapse the likely sparse codebook down only to + actually represented values/words. This collapsing needs to be + indexed as map-valueless books are used to encode original entry + positions as integers. + + Second, we reorder all vectors, including the entry index above, + by sorted bitreversed codeword to allow treeless decode. */ + + /* perform sort */ + ogg_uint32_t *codes=_make_words(s->lengthlist,s->entries,c->used_entries); + ogg_uint32_t **codep=alloca(sizeof(*codep)*n); + + if(codes==NULL)goto err_out; + + for(i=0;i<n;i++){ + codes[i]=bitreverse(codes[i]); + codep[i]=codes+i; + } + + qsort(codep,n,sizeof(*codep),sort32a); + + sortindex=alloca(n*sizeof(*sortindex)); + c->codelist=_ogg_malloc(n*sizeof(*c->codelist)); + /* the index is a reverse index */ + for(i=0;i<n;i++){ + int position=codep[i]-codes; + sortindex[position]=i; + } + + for(i=0;i<n;i++) + c->codelist[sortindex[i]]=codes[i]; + _ogg_free(codes); + + + c->valuelist=_book_unquantize(s,n,sortindex); + c->dec_index=_ogg_malloc(n*sizeof(*c->dec_index)); + + for(n=0,i=0;i<s->entries;i++) + if(s->lengthlist[i]>0) + c->dec_index[sortindex[n++]]=i; + + c->dec_codelengths=_ogg_malloc(n*sizeof(*c->dec_codelengths)); + for(n=0,i=0;i<s->entries;i++) + if(s->lengthlist[i]>0) + c->dec_codelengths[sortindex[n++]]=s->lengthlist[i]; + + c->dec_firsttablen=_ilog(c->used_entries)-4; /* this is magic */ + if(c->dec_firsttablen<5)c->dec_firsttablen=5; + if(c->dec_firsttablen>8)c->dec_firsttablen=8; + + tabn=1<<c->dec_firsttablen; + c->dec_firsttable=_ogg_calloc(tabn,sizeof(*c->dec_firsttable)); + c->dec_maxlength=0; + + for(i=0;i<n;i++){ + if(c->dec_maxlength<c->dec_codelengths[i]) + c->dec_maxlength=c->dec_codelengths[i]; + if(c->dec_codelengths[i]<=c->dec_firsttablen){ + ogg_uint32_t orig=bitreverse(c->codelist[i]); + for(j=0;j<(1<<(c->dec_firsttablen-c->dec_codelengths[i]));j++) + c->dec_firsttable[orig|(j<<c->dec_codelengths[i])]=i+1; + } + } + + /* now fill in 'unused' entries in the firsttable with hi/lo search + hints for the non-direct-hits */ + { + ogg_uint32_t mask=0xfffffffeUL<<(31-c->dec_firsttablen); + long lo=0,hi=0; + + for(i=0;i<tabn;i++){ + ogg_uint32_t word=i<<(32-c->dec_firsttablen); + if(c->dec_firsttable[bitreverse(word)]==0){ + while((lo+1)<n && c->codelist[lo+1]<=word)lo++; + while( hi<n && word>=(c->codelist[hi]&mask))hi++; + + /* we only actually have 15 bits per hint to play with here. + In order to overflow gracefully (nothing breaks, efficiency + just drops), encode as the difference from the extremes. */ + { + unsigned long loval=lo; + unsigned long hival=n-hi; + + if(loval>0x7fff)loval=0x7fff; + if(hival>0x7fff)hival=0x7fff; + c->dec_firsttable[bitreverse(word)]= + 0x80000000UL | (loval<<15) | hival; + } + } + } + } + } + + return(0); + err_out: + vorbis_book_clear(c); + return(-1); +} + +long vorbis_book_codeword(codebook *book,int entry){ + if(book->c) /* only use with encode; decode optimizations are + allowed to break this */ + return book->codelist[entry]; + return -1; +} + +long vorbis_book_codelen(codebook *book,int entry){ + if(book->c) /* only use with encode; decode optimizations are + allowed to break this */ + return book->c->lengthlist[entry]; + return -1; +} + +#ifdef _V_SELFTEST + +/* Unit tests of the dequantizer; this stuff will be OK + cross-platform, I simply want to be sure that special mapping cases + actually work properly; a bug could go unnoticed for a while */ + +#include <stdio.h> + +/* cases: + + no mapping + full, explicit mapping + algorithmic mapping + + nonsequential + sequential +*/ + +static long full_quantlist1[]={0,1,2,3, 4,5,6,7, 8,3,6,1}; +static long partial_quantlist1[]={0,7,2}; + +/* no mapping */ +static_codebook test1={ + 4,16, + NULL, + 0, + 0,0,0,0, + NULL, + 0 +}; +static float *test1_result=NULL; + +/* linear, full mapping, nonsequential */ +static_codebook test2={ + 4,3, + NULL, + 2, + -533200896,1611661312,4,0, + full_quantlist1, + 0 +}; +static float test2_result[]={-3,-2,-1,0, 1,2,3,4, 5,0,3,-2}; + +/* linear, full mapping, sequential */ +static_codebook test3={ + 4,3, + NULL, + 2, + -533200896,1611661312,4,1, + full_quantlist1, + 0 +}; +static float test3_result[]={-3,-5,-6,-6, 1,3,6,10, 5,5,8,6}; + +/* linear, algorithmic mapping, nonsequential */ +static_codebook test4={ + 3,27, + NULL, + 1, + -533200896,1611661312,4,0, + partial_quantlist1, + 0 +}; +static float test4_result[]={-3,-3,-3, 4,-3,-3, -1,-3,-3, + -3, 4,-3, 4, 4,-3, -1, 4,-3, + -3,-1,-3, 4,-1,-3, -1,-1,-3, + -3,-3, 4, 4,-3, 4, -1,-3, 4, + -3, 4, 4, 4, 4, 4, -1, 4, 4, + -3,-1, 4, 4,-1, 4, -1,-1, 4, + -3,-3,-1, 4,-3,-1, -1,-3,-1, + -3, 4,-1, 4, 4,-1, -1, 4,-1, + -3,-1,-1, 4,-1,-1, -1,-1,-1}; + +/* linear, algorithmic mapping, sequential */ +static_codebook test5={ + 3,27, + NULL, + 1, + -533200896,1611661312,4,1, + partial_quantlist1, + 0 +}; +static float test5_result[]={-3,-6,-9, 4, 1,-2, -1,-4,-7, + -3, 1,-2, 4, 8, 5, -1, 3, 0, + -3,-4,-7, 4, 3, 0, -1,-2,-5, + -3,-6,-2, 4, 1, 5, -1,-4, 0, + -3, 1, 5, 4, 8,12, -1, 3, 7, + -3,-4, 0, 4, 3, 7, -1,-2, 2, + -3,-6,-7, 4, 1, 0, -1,-4,-5, + -3, 1, 0, 4, 8, 7, -1, 3, 2, + -3,-4,-5, 4, 3, 2, -1,-2,-3}; + +void run_test(static_codebook *b,float *comp){ + float *out=_book_unquantize(b,b->entries,NULL); + int i; + + if(comp){ + if(!out){ + fprintf(stderr,"_book_unquantize incorrectly returned NULL\n"); + exit(1); + } + + for(i=0;i<b->entries*b->dim;i++) + if(fabs(out[i]-comp[i])>.0001){ + fprintf(stderr,"disagreement in unquantized and reference data:\n" + "position %d, %g != %g\n",i,out[i],comp[i]); + exit(1); + } + + }else{ + if(out){ + fprintf(stderr,"_book_unquantize returned a value array: \n" + " correct result should have been NULL\n"); + exit(1); + } + } +} + +int main(){ + /* run the nine dequant tests, and compare to the hand-rolled results */ + fprintf(stderr,"Dequant test 1... "); + run_test(&test1,test1_result); + fprintf(stderr,"OK\nDequant test 2... "); + run_test(&test2,test2_result); + fprintf(stderr,"OK\nDequant test 3... "); + run_test(&test3,test3_result); + fprintf(stderr,"OK\nDequant test 4... "); + run_test(&test4,test4_result); + fprintf(stderr,"OK\nDequant test 5... "); + run_test(&test5,test5_result); + fprintf(stderr,"OK\n\n"); + + return(0); +} + +#endif |